Elastic Force Enhancing Structure of Self-Opening/Closing Umbrella

ABSTRACT

An elastic force enhancing structure is provided for a center post of a self-opening/closing umbrella. The center post includes inner, intermediate, and outer tubes telescopically connected. A primary spring is received in the center post. The outer tube receives therein an elastic force enhancing spring and a joint sleeve that has an upper end forming an inner flange extends inwardly and a lower end forming an outer flange extends outwardly. The joint sleeve is fit over an upper end of the primary spring to have the inner flange and the upper end of the primary spring in abutting engagement. The elastic force enhancing spring has a lower end fit over the joint sleeve so that the lower end is in abutting engagement with the outer flange. As such, the elastic force enhancing spring is coupled, via the joint sleeve, to the primary spring to provide an extended configuration.

(a) TECHNICAL FIELD OF THE INVENTION

The present invention generally relates to the field of self-opening/closing umbrellas, and more particularly to a structural improvement of a center post of a self-opening/closing umbrella.

(b) DESCRIPTION OF THE PRIOR ART

The extension of a center post of a self-opening/closing umbrella is realized with springs arranged inside the center post. However, due to the constraint imposed by the limited internal space of an inner tubular section of the center post, a primary spring does not have a sufficiently powerful spring force. Specifically, the primary spring has an outside diameter that is limited by an inside diameter of the inner tubular section and consequently, it is not possible to adopt a spring having an enlarged outside diameter to provide an increased elastic force. Further, to allow for normal movement of a bullet head inside the center post, the primary spring has a wire diameter that is limited by the size of the bullet head. Consequently, it is not possible to adopt a spring having an enlarged wire diameter to provide an increased elastic force. Further, due to the internal space of the center post in a retracted condition being very limited, the primary spring is subjected to an additional constrain in respect of the turns thereof. Due to such various constraints, the primary spring used in the conventional self-opening/closing umbrella is insufficient in respect of the elastic force provided thereby, commonly leading to incomplete extension of the center post. Such a known structure is apparently imperfect and further improvements are desired.

SUMMARY OF THE INVENTION

To solve the technical issues discussed herein, the present invention adopts a technical solution, which provides an elastic force enhancing structure of a self-opening/closing umbrella that generally comprises an umbrella center post composed of an inner tube, an intermediate tube, and an outer tube sequentially and telescopically fit to each other. A primary spring is arranged in the umbrella center post. The features are that the outer tube further comprises an elastic force enhancing spring arranged therein. The elastic force enhancing spring is coupled, via a joint sleeve, to an upper end of the primary spring so as to provide an extended configuration.

The joint sleeve has an upper end from which an inner flange extends inwardly. The joint sleeve is fit over the upper end of the primary spring. The inner flange is set in abutting engagement with the upper end of the primary spring. The joint sleeve has a lower end from which an outer flange extends outwardly. The elastic force enhancing spring is fit over the joint sleeve in such a way that a lower end thereof is set in abutting engagement with the outer flange. The elastic force enhancing spring has an outside diameter that is set in gap-intervened fitting with an inner wall of the outer tube and an inside diameter that is set in gap-intervened fitting with an outer wall of the joint sleeve.

An outer tube advance ejection spring is arranged between the outer flange of the joint sleeve and an upper end of the intermediate tube. The outer tube advance ejection spring has a spring force smaller than spring force of the elastic force enhancing spring.

The outer flange of the joint sleeve comprises a notch formed therein to receive an upper end of the outer tube advance ejection spring to insert and position therein.

The outer tube receives therein a cord sleeve that has a lower end inserted into the primary spring.

The joint sleeve has an upper end from which an outer flange extends outwardly. The primary spring has an upper end that is fit to the joint sleeve in such a way that the outer flange and the upper end of the primary spring form abutting engagement. The joint sleeve has a lower end from which an inner flange extends inwardly. The joint sleeve is fit over a lower end of the elastic force enhancing spring in such a way that the inner flange and the lower end of the elastic force enhancing spring form abutting engagement. The elastic force enhancing spring has an outside diameter that is set in gap-intervened fitting with an inner wall of the joint sleeve.

The intermediate tube has an upper end to which an intermediate plug is mounted to retain an upper end of the primary spring. A secondary spring is arranged between the intermediate plug and the joint sleeve. The secondary spring has an inside diameter that is set in gap-intervened fitting with an inner wall of the outer tube. The secondary spring has an upper end fit over the joint sleeve and set in abutting engagement with the outer flange.

In summary, the present invention comprises a joint sleeve that is arranged inside an outer tube and coupled to an upper end of a primary spring and the joint sleeve is used to couple to an elastic force enhancing spring, whereby in opening an umbrella, the overall elastic force of the umbrella is enhanced and in closing the umbrella, the spring forces of the two spring counteract each other so as to reduce the force required for compression in closing the umbrella, making it more practical.

The foregoing objectives and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.

Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing a first embodiment of the present invention in an umbrella closed condition.

FIG. 2 is a schematic view showing the first embodiment of the present invention in an umbrella opened condition.

FIG. 3 is a schematic view showing the first embodiment of the present invention in an umbrella cover collapsed condition.

FIG. 4 is a schematic view showing the first embodiment of the present invention with a center post advance ejection spring additionally included.

FIG. 5 is a schematic view showing a second embodiment of the present invention.

FIG. 6 is a schematic view showing a third embodiment of the present invention in an umbrella cover collapsed condition.

FIG. 7 is a schematic view showing the third embodiment of the present invention in an umbrella opened condition.

FIG. 7A is an enlarged view of portion A of FIG. 7.

FIG. 7B is an enlarged view of portion B of FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.

FIGS. 1, 2, and 3 show a first embodiment of the present invention, which is an umbrella center post including a single pull cord 5. The present invention comprises an umbrella center post and a primary spring 4 that are identical to known structures and the umbrella center post is also composed of an inner tube 1, an intermediate tube 2, and an outer tube 3 sequentially and telescopically fit to each other. In a practical application, the inner tube 1 has a lower end to which a bottom plug 11 is fit and the outer tube 3 has an upper end to which a top plug 31 is fit. Besides the primary spring 4, a pull cord 5 and a cord sleeve 6 are also arranged inside the umbrella center post. The cord sleeve 6 has an upper end fixed to the top plug 31 and a lower end located in the intermediate tube 2. The present invention also comprises a joint sleeve 7 and an elastic force enhancing spring 8 arranged in the outer tube 3. A self-opening/closing umbrella according to the present invention may adopt the same principle of operation as a conventionally used structure. As shown in FIG. 1, in a completely retracted condition, a lower end of the outer tube 3 is received in a handle and retained and fixed therein. As shown in FIG. 2, when a push knob provided on the handle is pressed down for the first time, the outer tube 3 is released and extended with a retention terminal 51 of the pull cord 5 being still fixed. Under the action of the pull cord 5, a runner is pulled upward to complete an umbrella opening operation. As shown in FIG. 3, when the push knob of the handle is pressed down for the second time, the retention terminal 51 is released and under the action of umbrella closing springs arranged on umbrella ribs, the umbrella ribs and an umbrella cover are both collapsed.

The features of the improvement made in the present invention generally reside in that the elastic force enhancing spring 8 is additionally provided and is arranged inside the outer tube 3 and the elastic force enhancing spring 8 is coupled via a joint sleeve 7 to an upper end of the primary spring 4 to provide an extended configuration, meaning the overall spring length is increased through such an arrangement of combination. The joint sleeve 7 has an upper end from which an inner flange 71 extends inwardly and a lower end from which an outer flange 72 extends outwardly. The joint sleeve 7 is fit over the upper end of the primary spring 4 in such a way that the inner flange 71 is set in an abutting and coupled engagement with the upper end of the primary spring 4 in order to prevent the primary spring 4 from stretching out of the joint sleeve 7 and extending further upward. The inner flange 71 is set in gap-intervened fitting with an outer wall of the cord sleeve 6. In other words, the upper end and a lower end of the primary spring 4 are respectively supported on the inner flange 71 and the bottom plug 11. The outer flange 72 is also set in gap-intervened fitting with an inner wall of the outer tube 3. The elastic force enhancing spring 8 has a lower end fit over the joint sleeve 7 in such a way that the lower end is set in an abutting and coupled engagement with the outer flange 72. In other words, the elastic force enhancing spring 8 is supported between the outer flange 72 of the joint sleeve 7 and the top plug 31. The elastic force enhancing spring 8 has an outside diameter that is set to form a gap with respect to the inner wall of the outer tube 3.

Referring to FIG. 4, to provide that the outer tube 3 is ejected from the handle earlier than the intermediate tube 2 when the push knob is pressed down to open the umbrella, an outer tube advance ejection spring 9 is arranged between the outer flange 72 of the joint sleeve 7 and an upper end of the intermediate tube 2. The outer tube advance ejection spring 9 has a spring force that is smaller than spring force of the elastic force enhancing spring 8, whereby the total elastic force of the umbrella center post of the present invention is equal to the spring force of the elastic force enhancing spring 8 subtracting the spring force of the outer tube advance ejection spring 9 and adding spring force of the primary spring 4. To achieve stable connection between the outer tube advance ejection spring 9 and the joint sleeve 7, the outer flange 72 of the joint sleeve 7 comprises a notch formed therein to receive an upper end of the outer tube advance ejection spring 9 to insert therein and it is preferable to have the upper end of the outer tube advance ejection spring 9 inserted, in a rotary manner, through the notch by one or two turns to provide the best connection therebetween.

FIG. 5 shows a second embodiment of the present invention. Based on the same principle of structure as described above, a joint sleeve 7′ is provided so as to be arranged in a manner opposite to the arrangement of the joint sleeve 7, where in an inwardly extending inner flange 71′ is formed on a lower end and an outwardly extending outer flange 72′ is formed on an upper end. The intermediate tube 2 has an upper end to which an intermediate plug 21 is mounted to retain the upper end of the primary spring 4. A secondary spring 10 is arranged between the intermediate plug 21 and the joint sleeve 7′. The secondary spring 10 has an inside diameter that is fit to the inner wall of the outer tube 3 in such a manner that a gap is formed therebetween. The secondary spring 10 has an upper end fit over the joint sleeve 7′ and is set in abutting and coupled engagement with the outer flange 72′. The outer flange 72′ is also fit to the inner wall of the outer tube 3 in such a manner that a gap is formed therebetween. The lower end of the elastic force enhancing spring 8 is fit in the joint sleeve 7′ in such a way that the lower end is set in abutting and coupled engagement with the inner flange 71′ and the upper end is in abutting and coupled engagement with the top plug 31.

FIGS. 6, 7, 7A and 7B show a third embodiment of the present invention, which is an umbrella center post including two pull cords. The present invention comprises an umbrella center post and a primary spring 4 that are identical to known structures and the umbrella center post is also composed of an inner tube 1, an intermediate tube 2, and an outer tube 3 sequentially and telescopically fit to each other. In a practical application, the inner tube 1 has a lower end to which a bottom plug 11 is fit and the outer tube 3 has an upper end to which a top plug 31 is fit. Besides the primary spring 4, pull cords 5, 51 and a cord sleeve 6 are also arranged inside the umbrella center post. The intermediate tube 2 has an upper end to which an intermediate plug 21 having a center forming a through hole is mounted. The intermediate plug 21 comprises a pulley 22 mounted at one side of the upper end thereof and has a lower end to which the cord sleeve 6 is fixed. The joint sleeve 7′ is arranged inside the intermediate tube 2 in such a way that the joint sleeve 7′ is arranged in a manner opposite to the arrangement of the joint sleeve 7 of the first embodiment and is fit outside the cord sleeve 6 and has a lower end from which an inner flange 71′ extends inwardly and an upper end from which an outer flange 72′ extends outwardly. The primary spring 4 has an upper end fit to the joint sleeve 7′ so that the upper end of the primary spring 4 is supported on the outer flange 72′. The inner flange 71′ is fit to an outer wall of the cord sleeve 6 in such a manner that a gap is formed therebetween. The elastic force enhancing spring 8 is fit over the cord sleeve 6 in such a way that the elastic force enhancing spring 8 has an upper end supported on a lower end of the intermediate plug 21 and the elastic force enhancing spring 8 has a lower end supported on the inner flange 71′. The joint sleeve 7′ has a length that is smaller than the cord sleeve 6, whereby whether the umbrella center post is in an extended condition or a retracted condition, the joint sleeve 7′ can be kept fitting over the cord sleeve 6 to ensure smooth retraction of the umbrella center post without being interfered with. The pull cord 5 has an upper end extending through the top plug 31 to couple to a runner 20 and a lower end extending through the cord sleeve 6 to couple to an upper end of a retention terminal 51. The other pull cord 5′ has a lower end that is also coupled to the upper end of the retention terminal 51 and an upper end extending through the cord sleeve 6 and the intermediate plug 21 and then wrapped around the pulley 22 to couple to a lower end of the outer tube 3.

It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.

While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. 

I claim:
 1. An elastic force enhancing structure of a self-opening/closing umbrella, which is mounted in an umbrella that has a center post including a single pull cord and a primary spring, the umbrella center post comprising an inner tube, an intermediate tube, and an outer tube sequentially and telescopically fit to each other, the inner tube having a lower end to which a bottom plug is fit, the outer tube having an upper end to which a top plug is fit, a cord sleeve having an upper end fixed to the top plug and a lower end located in the intermediate tube, the improvements comprising an elastic force enhancing spring additionally provided inside the outer tube, the elastic force enhancing spring being coupled via a joint sleeve to an upper end of the primary spring to provide an extended configuration.
 2. The elastic force enhancing structure of the self-opening/closing umbrella according to claim 1, wherein the joint sleeve has an upper end from which an inner flange extends inwardly, the joint sleeve being fit over the upper end of the primary spring, the inner flange being set in abutting engagement with the upper end of the primary spring, the joint sleeve having a lower end from which an outer flange extends outwardly, the elastic force enhancing spring being fit over the joint sleeve in such a way that a lower end thereof is set in abutting engagement with the outer flange, the elastic force enhancing spring having an outside diameter that is set in gap-intervened fitting with an inner wall of the outer tube and an inside diameter that is set in gap-intervened fitting with an outer wall of the joint sleeve.
 3. The elastic force enhancing structure of the self-opening/closing umbrella according to claim 1, wherein an outer tube advance ejection spring is arranged between the outer flange of the joint sleeve and an upper end of the intermediate tube, the outer tube advance ejection spring having a spring force smaller than spring force of the elastic force enhancing spring.
 4. The elastic force enhancing structure of the self-opening/closing umbrella according to claim 1, wherein the joint sleeve has an upper end from which an outer flange extends outwardly, the primary spring having an upper end that is fit to the joint sleeve in such a way that the outer flange and the upper end of the primary spring form abutting engagement, the joint sleeve having a lower end from which an inner flange extends inwardly, the joint sleeve being fit over a lower end of the elastic force enhancing spring in such a way that the inner flange and the lower end of the elastic force enhancing spring form abutting engagement, the elastic force enhancing spring having an outside diameter that is set in gap-intervened fitting with an inner wall of the joint sleeve.
 5. The elastic force enhancing structure of the self-opening/closing umbrella according to claim 1, wherein an outer tube advance ejection spring is arranged between an outer flange of the joint sleeve and an upper end of the intermediate tube, the outer tube advance ejection spring having a spring force that is smaller than spring force of the elastic force enhancing spring.
 6. The elastic force enhancing structure of the self-opening/closing umbrella according to claim 1, wherein the joint sleeve is oppositely arranged in such a way that a lower end thereof comprising an inner flange extending inwardly therefrom and an upper end thereof comprising an outer flange extending outwardly therefrom, the intermediate tube having an upper end to which an intermediate plug is mounted to retain an upper end of the primary spring, a secondary spring being arranged between the intermediate plug and the joint sleeve, the secondary spring having an inside diameter that is fit to an inner wall of the outer tube in such a manner that a gap is formed therebetween, the secondary spring having an upper end fit over the joint sleeve and set in abutting engagement with the outer flange, the outer flange being fit to an inner wall of the outer tube in such a manner that a gap is formed therebetween, the elastic force enhancing spring having a lower end fit in the joint sleeve in such a way that the lower end is set in abutting engagement with the inner flange and the upper end is in abutting engagement with the top plug.
 7. An elastic force enhancing structure of a self-opening/closing umbrella, which is mounted in an umbrella that has a center post including two pull cords and a primary spring, the umbrella center post comprising an inner tube, an intermediate tube, and an outer tube sequentially and telescopically fit to each other, the inner tube having a lower end to which a bottom plug is fit, the outer tube having an upper end to which a top plug is fit, wherein besides the primary spring, two pull cords and a cord sleeve are arranged inside the umbrella center post, the intermediate tube having an upper end to which an intermediate plug having a center forming a through hole is mounted, the cord sleeve having an upper end fixed to the intermediate plug, the improvements comprising an elastic force enhancing spring additionally provided inside the intermediate tube, the elastic force enhancing spring being coupled via a joint sleeve to an upper end of the primary spring to provide an extended configuration.
 8. The elastic force enhancing structure of the self-opening/closing umbrella according to claim 7, wherein the joint sleeve is fit outside the cord sleeve and has a lower end from which an inner flange extends inwardly and an upper end from which an outer flange extends outwardly, the primary spring having an upper end fit to the joint sleeve so that the upper end of the primary spring is supported on the outer flange, the elastic force enhancing spring being fit over the cord sleeve in such a way that the elastic force enhancing spring has an upper end supported on a lower end of the intermediate plug and the elastic force enhancing spring has a lower end supported on the inner flange.
 9. The elastic force enhancing structure of the self-opening/closing umbrella according to claim 7, wherein the intermediate plug comprises a pulley mounted at one side of the upper end thereof, one of the pull cords having an upper end extending through the top plug to couple to a runner and a lower end extending through the cord sleeve to couple to an upper end of a retention terminal, the other one of the pull cords having a lower end that is coupled to the upper end of the retention terminal and an upper end extending through the cord sleeve and the intermediate plug and then wrapped around the pulley to couple to a lower end of the outer tube. 